The cruise control button on our 2007 Camry recently popped out of the end of the stalk. Searching online, I found that there were many instances of this problem, not only on the Camry but on other Toyotas as well.
When it pops out, the little copper piece that makes and breaks the connection with the contacts on the stalk will likely fall out of the button. Reinserting this copper piece, with the proper orientation, and carefully snapping the button back in, while pressing down on the contacts with a jeweler's flat blade screwdriver (so they slide in rather than being bent back) fixed the problem, for now. saved me the $78 cost of a new stalk with a new switch.